If the shape of a waveform signal passing through a transmission path is disturbed for some reason and thus the signal intended by the command source cannot be maintained until the signal reaches the command destination, a network transmission failure occurs. Therefore, an analysis of a physical layer level of the network is required as a diagnosis of such a transmission failure.
As a related-art example of a waveform signal analysis and as a related-art example intended to easily conduct a communication analysis by presenting a communication sequence and a physical amount in such a manner that the communication sequence and physical amount are associated with each other, for example, there has been proposed a communication test apparatus where “display means 108 disposes and displays, in chronological order, the sequence log display and power log display 9 showing the presence or absence of a communication from the power log information in a distinguishable manner” (for example, see Patent Document 1).
Also, as a related-art example intended to detect a communication interference wave by controlling a parameter as appropriate with respect to display of an analysis result, for example, there has been proposed a digital modulation signal evaluation apparatus where “a threshold setup unit 37 obtains a threshold R for determining the presence or absence of an interference wave on the basis of a modulation error ratio of a sub-carrier not included in an interference range expected to be interfered with by a interference wave among stored modulation error ratios and a determination unit 38 compares the threshold R with the modulation error ratio of the sub-carrier included in the interference range so as to determine whether there is an interference wave, and displays a result of the determination” (for example, see Patent Document 2).
Among related-art examples of a physical layer level analysis are the above-mentioned Patent Document 1 and a transmission signal analysis apparatus (for example, see Patent Document 3) that previously sets an ideal pilot signal for an OFDM-type transmission signal and analyzes an actual pilot signal using the ideal pilot signal.